Various communication systems are well understood in the art. For example, the Smartnet trunked radio communication system as manufactured and sold by Motorola, Inc. allows a relatively small number of radio communication resources to be flexibly allocated amongst a considerably larger number of radio users.
In many such systems, groups, of users having common communication interests are grouped into talk groups. For example, a fleet of delivery vans might be arranged as a first talk group, and a fleet of cement delivery trucks might be grouped as a second talk group. These radios would be programmed with appropriate talk group affiliation information, and that same information would be stored for use by a resource controller. So configured, when a member of a particular talk group initiates a communication, the resource controller, in addition to allocating an appropriate communication resource to support the communication, will also utilize the talk group affiliation information to ensure that other relevant talk group members become a part of the communication as well.
Some particularly large communication systems have multiple sites. Each site typically includes a resource controller and a set of communication resources that are assignable to service communication units within the coverage area that is serviced by that particular site. So configured, in order to support a communication involving members of a common talk group that are themselves distributed over two or more sites, a communication resource must be assigned at each site. To date, in such systems as the Smartzone communication system as manufactured and sold by Motorola, Inc., a central resource controller has been utilized to control the assignment activities of the resource controllers located at each site. For many applications, this configuration provides excellent service. There may be other situations, however, where such centralized control may be less desirable.
Accordingly, a need exists for an alternative way to ensure talk group participation across multiple sites.